Solution

The SOAP header is an optional section in the SOAP envelope, although some WSDL files require that a SOAP header is passed with each request. A SOAP header contains application-specific context information (for example, security or encryption information) that is associated with the SOAP request or response message. There is only one SOAP header section in a SOAP request. If the SOAP header element is present, it must be the first child element of the envelope element. SOAP headers can be input, output, or input and output, and you do not need to specify them in the WSDL file.